The F1 EVO plans are becoming available, so work
begins simultaneously with the canopy and fuselage that has already
I've started the Horizontal Stabilizer (HS) and I've
had my "tail jig" set up for about 9 months. Time to put it to use. I
bought pre made hinge brackets from Avery. I mounted them on the
horizontal member of the jig. The 2x2 aluminum tube has of course been
stable dimensionally since I erected it last fall.
Bracket alignment on this square tubing surface is
easy. I marked the center of the brackets and marked the perpendicular
lines on the jig with a speed square. The centerlines on the jig was
done with a 1 foot and 4 foot ruler. The brackets are positioned and
squared with a speed square and clamped, then drilled and screwed into
Now that the jig is up (HAH!) it's time to build the
HS to sit on it. The plans are very complete for drilling the channels
and doublers that become the backbone of the HS. Measuring, and
measuring again, drilling #40, and drilling to #30 and deburring
took over 4 hours. The new EVO mods include extra doublers
to reinforce the tail, so the HS channel has doublers on the front and
the back. That makes for a pretty thick assembly. I'm glad I had a high
speed air drill for this, because a battery drill would never keep up.
For a building surface, I bought a laminated 10 foot
beam. My 2x4 work table is pretty square, but comes up short. You need
9 feet, and I would have had to build an extension. It's easier to buy
a nice rigid flat beam that will ensure your work surface is very flat.
You want to have a flat surface so you do not induce any twist in the
HS (horizontal stabilizer) during construction. I checked the beam
with a digital level to ensure it was consistent from end to end.
The HS rear spar is a combination of two tapered
aluminum channels and a thick pair of tapered aluminum doublers
on the aft side, and a funky shaped aluminum doubler on the front side.
The idea is to align everything and drill it all together very flat and
very sturdy. The plans has detailed measurements for every rivet and
bolt hole in this process.
In the picture above you can see the two pieces of
aluminum channel and the two aft doublers aligned, drill and clekoed
In the picture below, you can see all the brackets
aligned with a center string. I drew a line down the center of the HS
channels and measured for the position of the pivot brackets. Per plans,
you work from the outside brackets inward, making damn sure you get
everything centered and aligned so that the elevator swings properly.
(doesn't bind). Before any of the HS construction started, I struck a
line from one end of my beam to the other. The channels were aligned
and centered on this. After positioning and drilling the two outer
brackets, I ran some twine through all of the brackets and clamped the
string down centered and taught at both ends. This helps insure that
all the pivot bracket holes are aligned.
This is where I deviated from the plans a bit. The
plans call for you to attach the pivot brackets and set the HS assy up
on the jig to back drill the forward doubler into position. Rather than
go to all that trouble, I merely removed the HS assy from the table,
re clekoed it and flipped in catywompus over the sides of my laminated
beam. Then I precisely aligned the fwd doubler and back drilled 4
holes. Just enough to cleko it in position. Then I flipped it back over
and clekoed everything back to the beam. The clekos barely go through
the second doubler, let alone grip the assy to the table/beam. But the
tips of the clekos do sit in the drilled holes in the wood enough to
hold everything stable.
The pic above shows the HS assy clekoed before I
flipped it over. Note the aft doublers are clekoed at the ends, but not
where the fwd doubler will be drilled to the assy. The grey piece
laying to the right side of the assembly is the new EVO edition double
doubler! There's some serious reinforcing going on in the tail
and with the new wings. I sure hope the plane flies fast enough to need
them! The company ship went 300 in a full power dive, so I think it'll
be plenty sturdy! And that was with a STOCK tail!
The fwd doubler measures 42 1/8". I found the center,
and centered it on the "back" of the HS assy. You have to be careful
that the edges of the doubler do not go over the edge of the HS
channel, otherwise it would interfere with the skins, and the edge
distance (ED) could be too small for strength (and "violate" 43.13).
Actually this was pretty easy to position and clamp in place.
I flipped the assy over the edge of the beam and
positioned it for drilling. This could easily be done over the corner
of a table. I added some clamps and began drilling.
I flipped the clamped assy over on it's side, resting
on the clamps, drilled 4 holes, flipped the assy back over again,
clekoed everything down and finished drilling the holes.
Once everything is drilled, deburred, and primed, it's
ready for riveting.
I clekoed the entire HS rear spar assy together just
to admire it. When riveting it, I removed the brackets and
flipped the HS assy on it's "face" and slid the ends off the end
of the beam/table. I clamped the assy to the table and worked about 3
rows of rivets at a time.
I was able to get the aft doublers riveted with my
pneumatic squeezer just fine. However the plans don't tell you what
rivets to use ( just "4" rivets, as in size 4). I used a AD4-6 in the
ends of the channel/aft doubler. But when riveting the two doublers and
the channel together, even an "8" rivet is too short. And the only size
longer in a size 4 rivet that comes with the kit is an "11", and there
are not enough of them. I'd have to cut them anyway. So this is where I
stumble to an abrupt halt and wait for clarification and more correct
parts from the Team Rocket home office. I have plenty of projects to
work on with this kit plane, but it's very frustrating to have to stop
Since it's raining cats and dogs, my holiday weekend
will be indoors. Darn. Have to build! Perhaps tomorrow will be nice
(4th of July).
2004 is over, and it was a great time. Flying and camping is always
fun. Even a couple heavy showers could not dampen the experience.
Time to get
back to building. The Vertical Fin (VF) is all but complete,
it's time to get back to the Horizontal Stabilizer (HS). On the
previous "emp" page you can see that I started the project on the
H-frame jig. I got the rear spar ready to rivet, then found out that I
was not provided with the correct rivets. That was corrected very
quickly by Team Rocket, but by the time the rivets came, I was already
working on the VF.
Soon as I
got back from OSH, I puttied my oops on the VF and also dragged the HS
back out. I had to customize some #4 rivets. With the two doublers and
steel brackets on the HS rear spar I had to use "10"
length rivets. They weren't supplied, so I cut down
11's. Most of the doubler areas take 4-8 and 4-6 rivets. My pneumatic
squeezer works well on 6 lengths, but doesn't seem to like 8 length and
longer. So I got out the 2x gun and the cup set and my trusty little
bucking bars and went to town.
The HS rear
spar is completed, except that the center bracket is not in place. That
area takes AN3 hardware, and is supposed to be drilled up and
bolted now. I thought it might interfere with mating up the forward
spar and center parts, so I skipped it for now. I went ahead
repositioned the HS rear spar on the H-frame jig, and I'm ready to build
the HS skeleton.
HS Front Spar
front spar is the next sub assembly to be constructed. You essentially
build it on top of the rear spar in the H-frame jig. I put the tip ribs
in position on the rear spar, trued them up, checked the HS for level
and no twist and went to town.
happened to have a scrap piece of 4 inch PVC pipe, so I used a hand saw
and cut a 5 1/6 inch piece to sit on the center of the rear
This is a support for construction the forward spar. The
spar has a flat central part, and the ends bend back toward the tip
easiest to measure all theses parts for drilling on the bench. The two
main aluminum channels also have to be trimmed to length. I
the doubler and the angles for drilling. On the HS3201 you really only
have to mark the outer areas of the fingers where they drill solely to
the HS002 channels. All the other holes will be drilled based
the other parts. This is one thick sandwich of parts!
This gets a
little tricky, but it makes sense
once you see it. You put the HS014 angles on top of the HS002
channels and align the outer flanges to 3 5/32. Make sure they sit
symmetrically about the bends on the HS002 flanges, and that they are
centered in the entire assembly. Clamp them tightly. I then drilled the
tip of each finger and clekoed them. Then I drilled the
4 innermost central holes and clekoed them. After
drilled and clekoed every other hole.
At this point,
I didn't understand the plans
and went down my own path. I removed all but about 6 clekos
the flat part of each HS002. Just enough to keep the parts straight. I
took the front spar assembly and flipped it over on it's back. I had
already drilled the tip holes. I aligned and centered the HS3201
doubler and clamped it down right over the HS002 with the cleko heads
protruding. I drilled the tips of the HS3201 through the HS002's and
clekoed them. I then drilled through the middle hole on the finger and
then drilled the closest hole to where the tip of the fingers on the
HS0014 was located and clekoed these holes. I then back drilled just
enough holes through the HS014's and the entire assembly to keep it
together, and removed the original HS014 clekoes.
that the original
HS014 clekoes would keep the HS3201 from sitting properly, and
make the holes a bit off center. I didn't find that to be a problem.
All of this is done through this point using a #40 bit, and after all
the holes are drilled, you drill up to #30. Any discrepancy in hole
location is taken up by the larger bit. I didn't find this to be a
problem what so ever. And I thought my technique to
easier than aligning the HS014's on the HS3201, match drilling them,
then trying to transfer the exact alignment on either side of the
HS002's. I found it much easier to do most of this drilling in assembly
on the support on top of the rear spar in the jig.
the HS Skeleton
ribs are easy to locate. Just
center them above the central ribs and clamp them to place. I drilled
the main ribs to the spars first, then back drilled for
ribs. Then it was just a matter of a LOT of bucking of a LOT of
different sized #4 rivets.
Big note here:
it is recommended rather late
in the plans NOT to rivet the tip into place at the very ends of the
assembly. Drill them, cleko them, but leave them removable so you can
get in there to buck rivets when the skins go on.
At this point
I went back and re-checked all
the dimensions. I have to say that having a digital level really speeds
things up and gives you confidence that you are plumb and level.
The tip ribs
are set, nutted to the
all-thread, so they should always stay straight. But I checked the rear
spar for level again and found that I had shifted it some. Just to be
safe, I went ahead and repositioned everything as necessary. I had
already pre drilled the ribs and deburred them, so it was just a matter
of getting them positioned, then back drilling them though the spars
and nose ribs.
dimensions are well set out in the
plans. The center ribs are easy to locate, and just use a speed square
in the pic above to set in position, then use and angle drill to drill
them in place. The root ribs are a little tricky due to the measurement
you have to set from center.
At this point,
my 4X gun came back from being
repaired at the Taylor factory in Florida. It was defective when it
came new. They repaired it at no charge and turn around time was a
little more than a week.
I had been
using a 2X gun on everything to
this point. I have to tell you that I will probably retire that 2X gun,
and just use the 4X as much as possible. It's much more controllable,
at lower air pressure, hits harder and requires fewer bucks to get the
rivets set. My hands don't hurt nearly so much as they did with the 2X.
And I don't screw up as many rivets!
is ready to finish. The rivets
in the center section are flush set to the rear. I had machine
countersunk these areas. The kit has 4-9 rivets for this entire area. I
used the 4-9's in the flush area, but opted to use 8's in the universal
rivet holes. 9's were too long, and if I cut them, I couldn't get them
any different than an 8. So the shop heads are smallish, but adequate.
The HS Skin
If you want to get a really pretty skin on your F1 (or any riveted
surface), I highly recommend that once you get the skin drilled and
clekoed in place that you GLUE or BOND the skins down just prior to
riveting. Pick the side you want the prettiest and glue that side to
the skeleton and cleko it for about 24 hours. On a side that you may
need to leave open until very last, you can still glue it prior to
assembly and get a better than average looking surface. Just wax or use
releasing agent on the mating surface of the skin and glue it down. The
next morning, just remove the clekos and pop the skin free. When you go
back to rivet it down, you will still get a better surface than if you
just bang rivets in bare metal parts. I'm kind of heavy handed and it
shows. I have puckers and deformations that aren't particularly pretty.
I wish I would have done this trick from the start. In the case of the
HS, I would glue the top surface completely down and use releasing
agent on the bottom where it's harder to see the results.
skeleton is complete. I marked the
centerlines on the flanges of the ribs and transferred them to the
H frame jig. Next, I have to position and clamp the skins, then design a
drill pattern for the #3 flush rivets that hold the skin on.
The plans do
not say that you use #3 rivets,
but this is kind of the "RV standard". Even though the F1 skins are
thicker, you don't need to step up to #4 rivets.
The plans also
do not give a spacing
requirement for rivets on the skin. I will be using 1 1/4 spacing as I
did on the VF. I still have my borrowed fan spacer. That makes the task
much quicker to accomplish, in my rookie opinion.
It looks like
a perfect weekend for flying,
so I probably won't get much done with the skins. But at this point, I
feel like I'm making very good progress. I'm having a lot of fun,
learning every day, and getting a lot of satisfaction from the building
I went flying
after work and fueled my Super
Decathlon. Our EAA Chapter 83 has a great lunch fly in tomorrow and it
is a must show. Considering there are hurricanes in Florida today, we
really lucked out. It was a nice cool 72 on the ground. Not bad for mid
August. What's this about global warming?
I got kinda restful. I had a
nice nap. Then I got restless. So I went to the basement to look at the
HS skins. Well, I put one in place. Well, I decided to clamp them down.
Well, might as well draw the centerlines for the flanges. I wasn't even
planning on working on the plane and ended up putting over 4 hours in,
getting the first HS skin drilled and clekoed. On just one side.
use a horizontal board as well
as vertical boards and clamps to hold the skins down. The tighter they
are to the skeleton, the prettier and more precise they are. I chose to
just use 2 vertical boards only, just like I did on the VF, and it
turned out just fine. What I did do, however, was make sure and press
the skin down flat with my fingers on either side of the drill mark.
And I started at the center of the skin and worked outward, pressing it
tight all the way. It was already fairly tight with the all
threaded vertical boards, but there was still some "slop". Perhaps it
would have been a bit better using 3 vertical boards. You
draw the line somewhere. It's a matter of diminishing returns
your investment... time and materials in this case versus potentially
better cosmetics. You can be the judge when I'm done.
The other HS
skin is set in place. I'm all
but done drilling the skin on the first side of the first
side on the HS. Next I'll go the the other side of the same
and finish drilling and clekoing that one. I think I'll barely have
enough clekos to get the job done. I think I have over 300 #40's. I may
need to get more, but I think this will be the biggest assembly I
produce on this entire project. So If I can work around it, I hope I
don't have to invest in any more clekos. But boy it sure does take a
blue million of those things!
first side, I did one small area at a time. Mark, drill, cleko, mark,
drill, cleko... about 8 holes at a time.
second skin, I decided to do things a little differently. I went ahead
and used the same 1x2's and clamped the skin in position. This time I
cranked the boards tight and marked both sides for drilling at the same
time. I started in the center of each side and marked all
"corners" from there. I loosened one end of the boards and
slipped the fan underneath. Then I went to the other side and marked the
same "corner". I had to drill the intersections and the ends
course to locate the fan spacer, but otherwise I drilled all the holes
at once... more or less. This saved a bunch of time.
that my centerlines transferred very accurately and I had to make very
little compensation when I actually drilled the holes. In a couple
places I determined the ribs and skin did not meet in perfect edge
alignment, so I had to fudge a couple places to either side of the
line. And at the HS014 angles I had to drill quite a ways out of line.
(quite a ways is like one rivet width).
skin took me over 4 hours to just get positioned and drilled. The
second skin took about 2. There's a big learning curve here, and I hope
to get on the more favorable side of it one of these days. Probably
with the NEXT kit plane project (if ever...).
Now that the
skins are drilled in position, I
need to trim the aft edges. It's easier to do this on a bending break
than with shears or dremmel. I'm going to mark the nominal edge
distance (I think it's 1 1/2" from the face of the rear spar) and then
take the skins to my friends at the local U. They have
large enough to take care of cutting these wider skins, and it
leaves an extremely nice edge. After that, I'll Debur and
(DB&D) the skeleton and skins, which will certainly include
to machine countersink some places that cannot be dimpled. Of course,
after that, I'll start riveting the flush #3 rivets.
on my riveting plans. When I
constructed the VF, I did most of the work on the tabletop, not in the
jig. Having drilled the skins in the H-frame jig, I think I like the
idea of bucking in the jig, if I can manage it. I think the skins will
look much better by the time I'm finished. Also, I wont remove all of
the vellum coating on the skins. The plan is to round off my soldering
iron and melt through enough of it along the rivet lines that I can
dimple and buck them without interference of the plastic.
I went ahead
and used a pencil type soldering
iron to remove the "vellum", or plastic protective coating, from the
drilled holes on the HS skins. It is necessary to remove this layer
prior to deburring and dimpling. The film on the HS skins is quite
thick, and in a few places, I had to drag the tip slowly, and even go
over some places twice. On areas where you only have to melt one side
of a strip to remove it, you can start lifting the material and then
pull the strip off as you drag the iron along ahead of peeling the
strip. It's not that easy when you have to do both sides
central line of holes.
I deburred and
dimpled the skins. On the
first skin, I had the male die just below the surface of the skin and
the carpet adjacent to the C-frame. That was a mistake! Also,
didn't keep my fingers tight on either side of the die when I wanged
the plunger with my rubber mallet. Consequently, there are smileys
around the dimples from the skin being bent down, and some of the
simples went off center on the second blow. None of these are part
scrapping problems, but the cosmetic result is not very pleasing.
dimpling the skins, I had to close the bend to make the skin sit better
on the HS skeleton. You might notice that there is considerable pull on
the VF skin on the Emp2 page, and the rivet closest to the leading edge
has a bunch of "pucker" around it. Hopefully I can avoid that with
I used 1
inch PVC clamped inside the bend and used my palms to press the angle
closed. I should have stuck with the 1x2 I was using initially, because
my palms made irregular waves in the skins. Those skins were pretty
tough to get closed!
tell in the pic above the difference in the open angle of the factory
skin and the manhandled skin. It took quite a bit of grunting to get it
closed just this much.
retrospect, I probably should have used a larger diameter pipe inside
the bend before pressing closed the bend angle. I think the profile of
the leading edges may have been more uniform and also
cosmetically pleasing. We'll just have to see if it affects performance.
I had not
drilled and bolted the center
bearing/bracket on the HS spar. Before finishing the skins, I
re-clekoed it onto the spar, got out a nice #12 drill bit and went at
it. Once I got through the aluminum and into the steel bracket, the bit
just wasn't quality enough (read: hard and sharp) to get the job done.
So I got out the corresponding cobalt Dewalt bit and punched through
the steel. I then used a large "titanium dipped"
junk!) bit and deburred the bottom of the hole.
torqued" (GOOTANTIGHT) AN3-6 bolts
with nylon stop nuts and washers on both sides. I put the bolt head on
the bearing side to be sure and have maximum clearance from the
elevators. Originally, the thickest washer left me nary a thread
outside the nut, so I went back and replaced the thick washer with a
thin one on the bolt head side and ended up with a couple good threads
the bends, I clekoed one skin
to the skeleton. I quickly determined that my arms are not long enough
to reach the first rivet with a bucking bar and gun. So now I am going
to solicit some help. I was hoping that I could complete this entire
project without help riveting, but alas, that's not the case. If I were
6'5" and had about another foot of reach, I could probably do it. At
5'6" I can only get to one side or the other. Now some serious
groveling is in order!
you have the HS free swinging on the hinges like in the pic below, be
VERY careful. When you start riveting you will feel the need to rotate
the HS away from you a bit. Remember that there are hinges down there
and they are stronger than that trailing edge of the skin. You CANNOT
rotate the piece very far or you will mangle the trailing edge of the
the bends in the HS skins, I
was ready to get help and bang those babies! My friend Bruce
delayed some honey-do's and came over to help.
We clekoed the
skins on the skeleton in the
frame, beginning at the middle ribs. We both looked at the situation
and decided that the ROOT nose ribs needed removed more than
end ribs, so we removed and installed them respectively.
The first REAL
order of business was to rivet
the nose ribs. Then we clekoed along the forward spar, flexed the metal
up from the opposite side and then bucked along the spar from the
center out. I decided to cleko every other hole. The last task of this
two man operation was to finish riveting along the middle rib to the
aft spar. I have a pneumatic squeezer that can easily reach
around the outer edges, and the ends are easy to buck, so I didn't
need my buddy's help on that area.
the HS skin riveting process
went like gangbusters. Once we got the rhythm down, we sailed right
through bucking the 3-4 flush rivets in the skin. A couple places
required longer #3 rivets.
as I was finishing along the
trailing end of the skins on one of the four "sides", I found that the
skin had slipped. It was off so much that I couldn't even get the
clekos in. So I got out the 40 bit and started drilling out rivets
until I could "coax" the skins into place. I was tired from about 9
hours of building and finally quit as soon as I got some of the holes
to cleko and line up pretty well. I thought it best to finish fixing
this little snafu after cogitating, ruminating and resting. In the mean
time, the next morning I went back to working on the control surfaces.
deliberation, I decided to just
re drill the holes on the HS. I only had to re drill the aft/spar (along
the bottom), and it didn't seem to affect the rivets. As in I didn't
have to move up to oops rivets... yet. (I have elsewhere!)
I went ahead
and riveted everywhere except
the ends where the counterbalance swings through. Then I got
ratchet strap and tied off the HS to the top jig member and pulled out
the hinge bolts. I carefully laid the HS on my table and admired my
lousy riveting job. The area I just fixed was fine, but I removed and
re-riveted about 40 or so other rivets. Not good to have to do it, but
I'll sleep better. I hand squeezed all of these rivets today.
I did this Labor Day, 2004 was
to cut the counterbalance notch in the HS skins. I used a regular cut
off wheel (not a heavy duty wheel), and it ripped right through the
skin where I measured and marked. I had to get this thing cut out,
because I started putting the elevators together, and of course I need
to be able to check the clearance and swing them on the HS.
October 2004 and I'm just back to
work on the HS. I was working on the VF and rudder, and now that is
down to finishing on the fiberglass. So I brought out the HS to work on
it's caps and the elevator caps.
the HS Counterbalance
I still had not
trimmed the counterbalance area of the
HS skins. I had marked them some time ago, but wanted to make sure
everything was correct. Well, today I checked them and my marks were
correct (as far as I can tell... remember, I've never done anything
like this before).
I put a disk in
the dremmel and went at it. I cut the
bottoms on both ends of the HS where the respective elevator c/b's
swing through. I fine tuned them with a hand file. I flipped the HS
over and cut the c/b's on the top side of the HS skins. Then I hand
filed in a little extra clearance in one area.
remembered reading in the plans that you have
to trim the skins following the CB outboard contour. So I used my
dremmel and cut one side. My whole goal here is to get a bunch of
fiberglass parts ready to work on so I can make big gooey messes all at
I wasn't sure how
to go about attaching the HS right
cap. I could leave it as is, put a doubler on the back of both sides
and shove the thing inside the HS skin. Then, like Randy Pflanzer likes
to do, just build up to the skin edge with micro balloons and
epoxy. I'm leaning toward cutting the fiberglass caps flush
then making flange/doublers and screwing the pieces on. As a matter of
fact, I'm leaning toward screwing all of the fiberglass pieces on
instead of pop riveting. I'm not sure making screws for everything is
that much more work than glassing around those gauwdaweful pop rivets.
At any rate, I've
worked about 10 hours today, and I'm
beat. I cleaned up the basement more than usual (you can't tell!) and
called it quits. I'll look at the HS caps again when I'm fresh and
decide how to proceed.
I worked on one
end at a time. I pinned each elevator
in place and marked the HS skins for trimming parallel to the
counterbalance outboard edge. I used a dremmel and a cutoff wheel to
trim back the skins, then a hand file to straighten it out. I also had
to trim the skin to allow the cb to swing through freely. I've allowed
for about 3/16 clearance all around. I can adjust this later when I'm
closer to finish trimming the edges.
I still hadn't
riveted the outboard rib on both ends
of the HS. As I was trimming for the end fiberglass caps, I went ahead
and finished the riveting. I also epoxied some rivets in holes that
were unfortunately inaccessible to squeeze due to the
being in the way. This isn't according to Hoyle, but I'd rather have a
nice solid rivet filing the hole than mess with a pop rivet. Those
things are horrid looking, and so far I haven't gotten any of them to
remotely resemble a squeezed rivet.
I'm going to use
#4 screws on all the caps. I used
scrap .025 for doublers on the left cap, just like the right. I pushed
the cap in under the HS skin and eyeballed it next to the elevator cap
(which is not finished). I marked the skin line on the cap and cut it
with a dremmel to size. Then I dressed it with a file.
I've drilled #40
holes and clekoed every other hole.
I'll countersink the fiberglass and then use soft rivet to attach the
doubler to the cap.
Once the doublers
are on, I used some pink polystyrene
board trimmed to shape to not only help contour the fiberglass cap, but
I'm also using it to close the HS skin in front of the elevator c/b.
So far I'm only
using one layer of BID cloth with a
copious layer of quick set epoxy. I'll trim to fit, then sand and get
this part close to being finished. Once all the caps (all 7 of them on
the empennage) are close to being finished, I'll re-epoxy them, probably
with micro balloons, then go through the normal fiberglass finishing
steps with filler and sanding primer.
Install the HS
Months have passed and I'm finally getting back to work. Remnants of
Hurricane Rita came through Indiana today, dumping rain for about 10
hours straight. I decided I might as well work on the Rocket. Since my
engine is no where to be seen and months overdue, I decided to
rearrange the basement a bit and begin to install the tail feathers.
They will of course have to come right back off, but hey, I need
something to work on.
The HS mounts on the flat area at the tail end (no surprise) of the
empennage. It bolts to the two thick vertical bars sticking out of the
back of the ship. It doesn't sit flat on the F-019 deck, but is in fact
about 1/4 inch above it at the rear spar of the HS. This aids in
setting the angle of incidence, which when finished is supposed to be
+1/2 degree. I take that to mean that the leading edge of the HS will
be .5 degrees UP at the front. That doesn't make sense to me, usually
the HS is supposed to fly down in order to raise/hold the nose up. As
is often the case, I am waiting for Mark to clarify that measurement.
When you set the HS in place, you have to shim it up. First, you level
the fuselage in various locations, then you set a 5/16" shim and a 1/4"
shim under the front and rear HS spars, respectively. In this case, I
used the recommended drill bit. Yes, a drill bit. How handy is that?
Already pre sized and just about the most convenient shape to get the
job done. Once the bits were in place, I clamped the rear HS spar to
the vertical bars (tail fork). Out comes the digital level. You are
shooting for completely flat (as in LEVEL) side to side. This was not
as easy as it sounds. I started by drilling the first hole located per
plans with a #40 bit. Then the next hole is drilled and all the
measurements re-checked to level. And then the next and the next hole
the same process. Then up to a #30 bit. As I went along, I didn't have
any fancy screw down type cleko thingies, so I left drill bits in the
holes and the HS clamped to the tail forks. Finally, I stepped up in
bit size and started inserting AN3 hardware. As I went along, I had to
jockey the HS a bit to keep it level. After the first two holes were
drilled, I also noticed the HS wasn't centered well enough, and had
shifted. So I had to tweak those initial holes a bit, too. Fortunately
using the method I chose mad correcting everything fairly easy, but it
was quite tedious and took me a couple hours.
Once the AN3's were ready to insert through the HS into the tail forks,
I made sure the holes were quite tight. You really don't want any slop
at this point. Later on, it may be necessary if I find things are not
as level as I thought, but for now, I want the HS to stay exactly where
I put it. I did not nut up the AN hardware, I just help both forks with
a quick clamp. You have to take the HS on an off a few times, so it
takes a lot less time if you just clamp it.
Now that the HS is level horizontally, it's time to set the incidence.
I took out the drill bit shims from under the edges of the spars and
made sure the midline of the spars was centered on the ship. My digital
level showed that the HS was sitting at about +.1 degree incidence, so
now I have to use aluminum sheet to shim up under the front spar until
I get it to +.5 degrees. I used various pieces of scrap until I got the
right combination of no more than two pieces. One piece would be
preferred, but it's probably going to be over .040. So a combination of
sizes will work best. I finally got the right combination of materials
and I think I will err to the +.6 degree side because when I bolt the
thing down I think it will compress somewhat.
In the pic above see that I have + .5 degree incidence.
NOTE THAT FOR THE EVO, the recommendation is ZERO incidence!
The +.5 degrees is for the stock F1. The difference between
the HS just sitting on the emp deck and tightening down all the AN3
bolts is about -.2 to -.3 degrees.! Don't think you can just lay the HS
on there and expect it to be the correct incidence after torquing down
When you drill
the holes for the AN3 bolts that go in the forward spar of the HS, the
OUTER 2 BOLTS go through the emp/fuselage LONGERONS. The other two
bolts can be
one inch (or more) inboard those two holes. I chose to put 6 bolts
through the HS
into the emp instead of 4. Yes, I had already spaced 4 holes inboard of
the longerons. Fortunately I had plenty of room for the two additional
VERY IMPORTANT bolts. I used standard nutplates on the inboard bolts,
but chose to use "corner" nutplates for the AN3 bolts in the longeron
Doesn't seem like I did much, but I worked on the F1 10 hours today. I
did a few other things in addition to working on the HS, but it was
slow going. After nearly four months of not building, I was really out
of the groove. I hope it comes back to me quickly!
Here it is, after Christmas '05 and I still don't have an engine. It's
hard to get motivated because of the repeated disappointment. Oh
well, time marches on. Spilt milk and all that. If necessary I'll let the legal
system try to straighten it out. Moore on that later.
Today, I finally bolted the HS in place. The tricky part is the bolts
that hold the front spar down on the deck at the empennage. After
leveling the fuse, I had two .040 shims in under the left side of the
front spar to level it up. One shim was all the way across the deck and
one was cut to cover just the left half of the deck. There is evidently
some twist in the fuselage, because
when it is balanced at the fuse and front spar, the aft end of the HS
is not completely level. It may be twisted as much as .3 degrees. Guess
I might have to contend with a turning tendency because of that. Of
course there are so many variables it's hard to tell where a turning
What I found out was that after you torque down the 10 each AN3
bolts holding HS on the airframe ( I put 6 in the HS front spar and
then 4 in the "forks"), the HS front spar shims were insufficient
and had to add another .032 shim on the left side.
Time to go back to the Vertical Fin page to see how it is installed!